Swivel caster



March 10, 1931. p, M N 1,796,044

SWIVEL GASTER Filed 'Feb. ll. 1930 dmm a Patented Mar. 10, 1931 UNITEDSTATES PATENT OFFICE PETER M. NAGY, OF ALLIANCE, OHIO, ASSIGNOR, BYMESNE ASSIGNMENTS, T TRANSUE AND WILLIAMS STEEL FORGING CORPORATION, OFALLIANCE, OHIO, A CORPORA- TION OF DELAWARE Application filed February11, 1930. Serial No. 427,521.

The invention relates to ball bearing swivel casters more particularly,of the heavy type used for industrial trucks, warehouse trucks orstorage bins, and for portable safes, cabinets and the like'. However,the improved caster may be of a smaller size to be used upon ofiice. andhousehold furniture, desks,

chairs and the like. 7

Swivel casters have been made including a plurality of sets of annularball bearings for journalling the caster wheel mounting to resist radialand thrust loading,-i n which one set of. balls lock the wheel mountingmember to the caster base plate member. 'However, these prior typesof-casters do not provide means for equally distributing the load to iall of the bearing balls. I I

One of the objects of the present invention is therefore to provide aswivel caster having an annular ball, bearing for resisting both radialand thrust loading in which the hearing balls hold the caster, wheelmounting frame member in assembled relationship with the baseplatemember, and in which means isprovided for equally distributing theloading to thebearing balls. j

Another object of the invention is to provide a caster in which thecomponent parts may-be fabricated by drop forging the same. Moreover,further objects ofthe invention are to provide a caster which may be adusted for wear, to provide a caster which may be readily and quicklylubricated," and to provide a caster which has a very simplified designand consequent low cost of production, a freeswivelling movement whensub ected to heavy loading, and great strength for resisting shocks andstrains. 7

These and other objects may be attainedby providing a construction, apreferred embodiment of which is hereinafter set. forth in detail, whichmay be stated in general terms as including a base plate member having aball seat and an annular ball raceway, a caster wheel mountingframemember having an adjustable ball'seat and an annular raceway, aball located between the ball seats, an annular series of balls locatedin the annular raceways holdingthe members in assembled relationship,means for-introducing SWIVEL CASTER the balls into the ball bearingannulus, a caster wheel, roller means mounting the caster wheel on thewheel mounting frame, and means for lubricating the caster wheel and theball bearings.

A preferred embodiment of the invention isshown in the accompanyingdrawings, in which- Figure 1 is a top plan view of the improved caster;

Fig. 2 is a section of the improved caster taken on the line 2-2, Fig. 1and showing the caster wheel in full; and

Fig. 3 is a section taken on the line 33, Fig. 2 showing the casterwheel mounting.

Similar numerals refer to corresponding parts throughout the severalfigures of the drawings. Y

The improved caster is illustrated generally at 4 and may include a baseplate member 5, a caster wheel mounting frame member 6 and a casterwheel 7. I

The base plate 5 is substantially rectangular in form and has cornerears 8, provided with apertures 9, through which bolts or the like maypass for securing the caster to the bottom of a truck, bin, safe orcabinet for providing a caster swivel therefor.

An annular flange 10 projects downwardly from the base plate 5 and isprovided with an annular ball raceway 11. The central under surface ofthe base plate 5 provided with a ball seat 12 which is spherical incontour. The annular raceway 11 and the spherical seat 12 have a commonvertical axis indicated at a in Fig. 2.

Theswivel frame 6 has an upwardly projecting annular flange 18, which isprovided with an annular ball raceway 1 1, and the frame is mounted forrotation about the vertical axis a and held in assembled relationshipwith the base plate 8 by an annular series of balls 15 located in theannular raceways 11 and 14. p

The mounting frame 6 is provided with a central screw threaded passage16 in which is a, provided in its upper surface, which has a sphericalcontour corresponding to the contour of the spherical seat 12.

A single ball bearing 19 is located between the base plate and mountingframe 6 and is seatedin the s :herical seats 12 and 18-. These seatspreferab y have a greater radius than the radius ofthe spherical ball 19for permitting relative axial adjustment between the seats 13 and- 18along the axisato compensate for wear "of the various parts;-This-adjiistment may be accomplished by inserting a preferably hexagonheaded wrench the hexagon shaped recess 20 in the member 17 for screwingthe member fromthe ball 19. V 3

It is pointed out that the horizontal axis '5 of the hall 19' is locatedabove "QiTClCOHSidET- ablyyottset from the horizontal axis a of'ctheannular series of hall beaffihg's 1'5 ffoflireason which will behere-matter described.

The base plate member and "mounting frame member may be assembledtogether by locating the flange 13 within the flange 10 and thenintroducing the balls 15 into the ,coacting raceways 11 and 14 throughthe'fpas sage 21 provided in the thickened 'boss22 located in theuppersurface of the mounting framefi: 'f j After asutficient number ofballs have been introduced intofthe-rapeway to fill the same, a 'plugscrew 23 1s inserted into the threadedop enin'g 21 for closing tliefsa fe.

It will be seen that-thehalls 15 hold'th'e'bas'e plate mounting frametogether -in assembled relationship 'an'dthat the opening 241- providedin the base plate 5 permits the balls 15 to be introduced lto'itheraceway through the passage '21, and permit -the plug '23 to be laterscrewdin o the passage 21. l

The single ball 1'9v is then inserted tl'irough the passage 16, themounting frame and is held in placeby inseftinfg the member 17 withinthe passage 16 to the position shown min 2 of thesdrawin gs. v v

The infojunting frame 6 1s provided with two do'w z'irdly di osedfo-rl'ie'd' legs for r I 1.;- t-he caster jwhe'el T, and the casterwheel n dunti'i-lg "may include 'a bolt 'a x le's'h att provided with anut- ZZhfor locking the Shiite to the forked legs '25. "The caster wheelTmay be ournalled on the axle shaft 15y providing the helical rollerbearings 28 between the hub '2'9of the wheel 7 and the shaft 26. i

' The roller 9/8 may lubricated by introc'h cing a lubricant through thecup 30-, press titted in the ohter. end of the longitudinal bore 31,provided in the a'xialshaft 26, and the bore 31 communicates withtheroller bearings 28 by means of a radial passageway. 32.

1 The bal bearings 15 may be lubricated through the cup 33 provided inan aperture he, located in the annular fia'nge IQ of I base plate 5 andcommunicating at 35 with 1 toward "or away the raceway 11; Sufficientlubricant will find its way from the raceway 11 and 14 to the ballbearing 19 for lubricating the same.

It is pointed out that a vertical plane (Z passing through the axis ofthe axle shaft 26 a's'shown in Fig; 2-, does not intersect the annulusof the ball bearings 15, but'is tangential thereto. With the, variousaxes a,'b, '0, and d locatedfsubsmntially,as shown in the drawings, andwith the 3 member 1-? ;substantially tightly fitted':aga instthe ball19, .a force applied upward along the vertical plane ,(Z acts about apoint which is at the center of the ball 19,;causing a large upwardthrust on the ball bearings 15 adjacent the plane (Z and a largedownward-thrust on the ball bearingsat a ipoint 'directly opposite, hilethe intermediate balls 1 5 will have thrusts "applied thereto varyingfrom one extreme to the other.

'Iclaim: I

1. A caster having a base plate member-3a flanges, an annular series orhalls s'aidracelwayspro'viding abearing between saidmemb'e'isps'aidballs holdii'ig the members in' as'- sembled relatiohship, a sphericalhall seat-on each oi-the manners, means for adjnsting one 1 fot the ballseatsrelativ-e t0 the-e ther, a single ball bearing interposedhetweenthe ball seats anda'wheel fie'urnaled in the" frame emb r ,r IfI. v

plate member; a-

fi'anre member, anannular flange "on each of 1 the "members, 'raceways'provided on the fl'a'i'ig'e's, an ahn'ular-serres of balls in saidmeways providing 'ahearing hetween said {memhers, said balls holding the'nr'ei'nbers' in assembled lelatioiiif'shi'p, aspher'ifcal ball "seat oneachof fine-imm rse single ball bearinginterp'osed' -'between the hallseats, the annulus otthe ball bearings having aveiti'cal axis in commonwith the vertical axis ol the single "ball spherical-bal-l seats, ahorizontal plane through thecenter of the single ball beingofiset hemthe* l1oriz'o'1'ital plane of said annulus, and a wheeljio irnaled'inthe frame member; I i a A oaster having a'b aseialatemember, a

nam member, meantime-sage on each of the member raceways provided; "onthe flanges, an an'n-ulaij series of balls in said racewa'ys pr'fovidinga; heialringbetweeh said menr,

hers, said balls holding the members assembled relationship, a sphericalball seat on each of the members, a single ball bearing interposedbetween the ball seats, a wheel having an axle carried by the frame outof center thereof, and a vertical plane passing through the axis of thewheel axle being tangential to the outer surface of the ball bearingannulus.

5. A caster having a base plate member, a frame member, an annularflange on each of the members, raceways provided on the flanges, anannular series of balls in said raceways providing a bearing betweensaid members, said balls holding the members in assembled relationship,a spherical ball seat on each of the members, a single ball bearinginterposed between the ball seats, a wheel journaled in the framemember, and means for lubricating the bearings and for lubricatin thewheel.

6. Z caster having a base plate member, a frame member, an annularflange on each of the members, raceways provided on the flanges, anannular series of balls in said raceways providing a bearing betweensaid members, said balls holding the members in assembled relationship,a spherical ball seat in the lower surface of the base plate, therebeing a threaded passage through the frame member, a screw threadedmember located in the passage having a spherical ball seat in its uppersurface, means in said last mentioned member for receiving a tool forrotatin the same to relatively adjust its spherical ba 1 seat toward oraway from the base plate spherical ball seat, a single ball bearinginterposed'between the ball seats, and a Wheel journaled in the framemember.

7. A caster having a base plate member, a frame member, an annularflangeon each of the members, raceways provided on the flanges, an annularseries of balls in said raceways providing a bearing between saidmembers, said balls holding the members in assembled relationship, therebeing an opening through the base plate member, there being a passage insaid frame member communi eating with its annular raceway adapted to belocated. below said opening for the introduction of said balls to saidraceway, a closure for said passage, spherical ball seats on each of themembers, a singleball bearing interposed between the ball seats, and awheel journaled in the frame member.

In testimony that'I claim the above I have hereunto subscribed my name.

PETER M. NAGY.

